Thread: Husky 223 muffler leaking oily residue

The CAT muffler on my Husky 223 trimmer is drooling an oily spooge. I don't know the history of this trimmer as I just bought it off craigslist. The owner said he couldn't get it running. I found cracked fuel lines, so I replaced the fuel lines and got it running, but there is a pretty good amount of oily residue inside the plastic shrouds and it is leaking out of the CAT muffler.
I'm trying to de-carbonize the motor by putting a little Seafoam in the mix and spraying Valve-tect decarbonizer spray down the carb throat and letting that sit, as per instructions.
Right now I can't get off the muffler because I think the hex screws are metric (4mm?) and some knucklehead put them on so tight it rounded off the closest hex key I had when I tried to remove them.
If I can get the muff off is there a way to get rid of the CAT?
Any suggestions are appreciated.